A method is known from DE 10 2012 015 846 A1 in which a modification of the surface geometry is produced by additional movements when dressing on the tool, said modification having a constant value in the generating pattern at least locally in a first direction on the tooth flank and being given by a function f(x) in a second direction which extends perpendicular to the first direction. This modification of the surface geometry of the tool is transferred to the workpiece by the diagonal generating method. A method is known from EP 1 995 010 A1 and WO 2010/060596A1 of dressing a worm in a crowning manner over its width during dressing by changes of the center distance. The center distance between the tool and the workpiece is furthermore changed in a crowning manner using this worm dressed in a crowning manner. The superposition of the two modifications hereby produced should minimize the twisting which is determined on two tooth traces. A diagonal generating method is known from DE3704607 A1 in which a worm is used whose flank angle on the left and right flanks decreases from a maximum value at one end of the worm to a minimum value at the other end of the worm to compensate the twisting of a helix crowning produced by a center distance change in the diagonal generating method. Methods are known from DE 196 248 42 A1 and DE 197 068 67 A1 in which a worm whose profile angle changes over its width is produced by a constant change of the position of the dresser with respect to the tool during dressing. The constant change of position of the dresser is determined on the basis of a desired modification. Methods are likewise known from DE 10 2005 030 846 A1 and DE 10 2006 061 759 A1 in which a worm is manufactured by corresponding dressing kinematics either over its total width with a constantly modified profile angle or the profile angle is modified over the worm width. A two-flank dressing for twist-free generating grinding is known from Kapp, Effizient and produktiv mit technologischer Flexibilitat, JOSE LOPEZ [Kapp, Efficient and Productive with Technological Flexibility, JOSE LOPEZ].
It is the object of the present disclosure to provide a method of producing a toothed workpiece which allows a greater flexibility in the specification of the desired modification of the surface geometry of the workpiece.
The present disclosure shows in a first aspect a method of producing a toothed workpiece having a modified surface geometry by a diagonal generating method by means of a modified tool. In a first variant at least two different modifications which can be produced by a modification of the dressing process of the tool and/or of the dresser used for dressing the tool and/or of the machining process of the workpiece are superposed for the production of the modification of the workpiece. In a second variant, which can optionally be combined with the first variant, a tool is used for producing the modification of the workpiece whose surface geometry comprises a modification which can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a linear and/or quadratic function, with the coefficients of this linear and/or quadratic function being formed by coefficient functions FFtC,1, FFtL,1 and/or FFtQ,1 in a second direction of the tool which extends perpendicular to the first direction. The first direction of the tool optionally has an angle ρFS≠0 with respect to the tool width direction. In a third variant, which can optionally be combined with the first and/or second variant, a tool is used for the modification of the workpiece whose surface geometry comprises a modification whose pitch and/or crowning varies in dependence on the angle of rotation of the tool and/or on the tool width position. Provision is made in accordance with the present disclosure, that the desired modification of the workpiece can be specified in the generating pattern as a second degree polynomial in the rolling angle wF and in the workpiece width position zF. The present disclosure thus makes possible the production of a plurality of modifications by a diagonal generating method by means of a modified tool.
The specific modification of the surface geometry of the tool produces a corresponding modification of the surface geometry of the workpiece by the diagonal generating method, said modification optionally having a modification superposed on it in accordance with the first variant which can be produced by a modification of the machine kinematics during the machining process of the workpiece. A modification of the surface geometry of the workpiece in accordance with the second variant and/or the third variant is optionally used. This modification of the surface geometry of the workpiece is optionally produced by a modification of the dressing procedure of the tool.
The present disclosure shows in a second aspect a method of producing a toothed workpiece having a modified surface geometry by a diagonal generating method by means of a modified tool. In a first variant for producing the modification of the workpiece, a tool is used whose surface geometry comprises a modification which can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a linear and/or quadratic function, with the coefficients of this linear and/or quadratic function being formed in a second direction of the tool which is perpendicular to the first direction by coefficient functions FFtC,1 for the constant portion and FFtL,1 for the linear portion and/or FFtQ,1 for the quadratic portion, with FFtC,1 depending in a non-linear manner on the position in the second direction and with FFtL,1 being non-constant. In a second variant, a tool can be used for producing the modification of the workpiece whose surface geometry comprises a modification whose pitch and/or crowning varies in dependence on the angle of rotation of the tool and/or on the tool width position and whose tooth thickness varies non-linearly in dependence on the angle of rotation of the tool and/or on the tool width position.
The present disclosure makes it possible by the modification in accordance with the present disclosure of the surface geometry of the tool to produce a large class of modifications of the surface geometry of the workpiece without producing shape deviations caused by the principle. Corresponding examples will be described in more detail in the following.
The modification produced by the modified tool optionally has a modification superposed on it which is produced by a change of the machine kinematics of the machining procedure of the workpiece. Such a modification can optionally be described in the generating pattern by a function which has a constant value at least locally in a third direction of the workpiece and is given by a function FKFt in a fourth direction of the workpiece which extends perpendicular to the third direction. The function FKFt optionally depends non-linearly on the position in the fourth direction. A substantially larger class of modifications can again be produced by the superposition of the two modifications.
A desired modification of the surface geometry of the workpiece is optionally specifiable, with a modification of the surface geometry of the tool suitable for producing this desired modification and optionally a change of the machine kinematics of the machining procedure of the workpiece suitable for this purpose being determined.
In accordance with an embodiment of the second aspect, the desired modification of the surface geometry of the workpiece can be specifiable in the generating pattern as a second degree polynomial in the rolling angle wF and in the workpiece width position zF. A method in accordance with the first aspect can therefore in particular be carried out using a tool in accordance with the second aspect and/or in combination with the method in accordance with the second aspect.
In accordance with the present disclosure, the desired modification of the surface geometry of the workpiece can be specifiable in the generating pattern as a specific second degree polynomial in the rolling angle wF and in the workpiece width position zF and/or as a selection of a plurality of such specific polynomials or of a sub-class of such polynomials and/or as any desired such polynomial.
In accordance with an embodiment of the present disclosure, at least one coefficient, and optionally a plurality of the coefficients of the polynomial as which the desired modification of the workpiece can be specified are freely selectable at least within specific conditions. It is conceivable that the desired modification is freely selectable as a sub-class of functions of such a polynomial at least within specific conditions so that not all the coefficients of the polynomial are specifiable. In a possible embodiment, however, all the coefficients of the polynomial can also be freely selectable within specific conditions.
The desired modification of the workpiece can, for example, be specifiable as a crowning, in particular as a crowning having freely selectable directions within specific conditions. Such a crowning can be produced without shape deviations caused by the principle in accordance with the present disclosure. The diagonal ratio can optionally be selected independently of the direction of the crowning and thus on the basis of technical production aspects.
In an embodiment, both a simple tooth trace crowning and a simple profile crowning can be specified or produced and further optionally any desired direction of the crowning disposed therebetween.
The present disclosure shows in a third aspect a method of producing a toothed workpiece having a modified surface geometry by a diagonal generating method by means of a modified tool. In a first variant at least two different modifications which can be produced by a modification of the dressing process of the tool and/or of the dresser used for dressing the tool and/or of the machining process of the workpiece are superposed for the production of the modification of the workpiece. In a second variant, which can optionally be combined with the first variant, a tool is used for producing the modification of the workpiece whose surface geometry comprises a modification which can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a linear and/or quadratic function, with the coefficients of this linear and/or quadratic function being formed by coefficient functions FFtC,1, FFtL,1 and/or FFtQ,1 in a second direction of the tool which extends perpendicular to the first direction. The first direction of the tool optionally has an angle ρFS≠0 with respect to the tool width direction. In a third variant, which can optionally be combined with the first and/or second variant, a tool is used for producing the workpiece whose surface geometry comprises a modification whose pitch and/or crowning varies in dependence on the angle of rotation of the tool and/or on the tool width position. In accordance with the present disclosure, the desired modification of the workpiece is specifiable in a first variant as a superposition of a plurality of crownings by directions freely selectable within specific conditions.
Such a superposition of a plurality of crownings by different directions can be described as a second degree polynomial in accordance with the present disclosure in the rolling angle and in the workpiece width position and therefore represents a sub-class of the polynomials specifiable in accordance with the first aspect.
Completely new possibilities of specifying the surface geometry of the workpiece result in accordance with the present disclosure from the directions of the crownings freely selectable at least within specific conditions. In accordance with the present disclosure, at least two crownings can optionally be specified with a respectively freely selectable direction whose superposition produces the desired modification of the workpiece.
A desired profile crowning can be specifiable in a second variant of the third aspect. It was, in contrast, not possible to influence the profile crowning in methods of the prior art. The tooth trace crowning can furthermore also be specifiable in a possible embodiment. It optionally has the desired profile crowning superposed on it.
The third aspect of the present disclosure may becombined with the first aspect and/or with the second aspect or a modification specified in accordance with the third aspect may be produced in accordance with the first and/or second aspects.
Embodiments of the first three aspects will be shown in more detail in the following:
The desired modification of the workpiece can optionally be produced by a superposition of a modification produced by a tool having a modified surface geometry and of modification produced by a change of the machine kinematics during the machining procedure of the workpiece. Enough degrees of freedom are hereby available to produce a modification of the workpiece which can be represented in the generating pattern as a second degree polynomial in the rolling angle and in the tool width position.
A tool can further more be used in accordance with the present disclosure whose surface geometry comprises a modification which can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a linear function, with the coefficients of this linear function being formed in a second direction of the tool which extends perpendicular to the first direction by the coefficient functions FFtC,1 for the constant portion and FFtL,1 for the linear portion. Alternatively or additionally, a tool can be used having a modification of its surface geometry whose pitch varies in dependence on the angle of rotation of the tool and/or on the tool width position. The inventor of the present disclosure has recognized that such a modification of the tool together with a modification produced by the change of the machine kinematics during the machining procedure of the workpiece is sufficient to produce the modifications which can be specified in accordance with the present disclosure. It is in particular not necessary that the surface geometry of the tool also has quadratic portions in the first direction or that the crowning varies in the tool width position. The modifications in accordance with the present disclosure can hereby be produced particularly easily.
Provision can further be made that the coefficient function FFtC,1 quadratically depends on the position in the second direction and/or that the coefficient function FFtL,1 linearly depends on the position in the second direction.
Provision can furthermore be made that the modification of the tool has a pitch which varies linearly in dependence on the angle of rotation of the tool and/or on the tool width and the tooth thickness varies quadratically in dependence on the angle of rotation of the tool and/or on the tool width position.
Provision can furthermore be made that the desired modification is broken down into at least one first modification and one second modification. The first modification can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a linear function, with the coefficients of this linear function being formed in a second direction of the tool which extends perpendicular to the first direction by the coefficient functions FFtC, 2 for the constant portion and FFtL, 2 for the linear portion. Alternatively or additionally, the first modification can be a modification whose pitch varies in dependence on the workpiece width position.
Provision is optionally made that the coefficient function FFtC,2 depends quadratically on the position in the second direction; and/or the coefficient function FFtL,2 linearly depends on the position in the second direction; and/or that the modification of the workpiece has a pitch which varies linearly in dependence on the angle of rotation of the workpiece and/or on the workpiece width position and the tooth thickness varies quadratically in dependence on the angle of rotation of the workpiece and/or on the tool workpiece position.
The second modification can be a modification which can be produced by a change of the machine kinematics during the machining process of the workpiece. Alternatively or additionally, the second can have a constant value in the generating pattern at least locally in a third direction of the workpiece and can be given by a function FKFt in a fourth direction of the workpiece which extends perpendicular to the third direction. The first and the third directions of the workpiece optionally do not coincide with one another. The function FKFt optionally depends non-linearly, and further optionally quadratically, on the position in the fourth direction.
Such a breakdown of the desired modification produces a first modification and a second modification of which the first can be produced by a corresponding modification of the surface geometry of the tool and wherein the second modification can be produced by a change of the machine kinematics during the machining process. The third direction in which the second modification has a constant value is defined solely by the macrogeometry of the workpiece and can therefore not be changed. The first direction in which the first modification can be described at least approximately by a linear function can, in contrast, be influenced by the selection of the diagonal ratio in the diagonal generating method.
The diagonal ratio in the diagonal generating machining of the workpiece is optionally independent, at least within specific conditions, of the desired modification of the workpiece which is in particular specifiable as a second degree polynomial and/or as a superposition of crownings. This is due to the fact that in the superposition in accordance with the present disclosure more degrees of freedom are available than are required for defining such a polynomial. The diagonal ratio therefore represents a parameter which is freely variable at least within specific conditions. A breakdown or superposition in accordance with the present disclosure can be found for each of these diagonal ratios and produces the desired second degree polynomial and/or the superposition of crownings.
In accordance with the present disclosure, the diagonal ratio can in particular be selectable independently of the direction or directions specifiable in accordance with the present disclosure of the desired crowning or crownings.
In addition to the desired modification of the workpiece specifiable as a second degree polynomial and/or as a superposition of crownings, an additional modification is optionally specifiable which has the former superposed on it. This additional modification can in particular be a modification which has a marked direction.
The diagonal ratio is optionally determined on the basis of the orientation of such a further desired modification. In accordance with the present disclosure, a plurality of new possibilities hereby result for specifying desired modifications.
In addition to the desired modification specifiable as a second degree polynomial and/or as a superposition of crownings, an end relief of the workpiece can in particular be specifiable in accordance with the present disclosure. The end relief optionally has the desired modification of the workpiece specifiable as a second degree polynomial and/or as a superposition of crownings and in particular one or more crownings superposed on it.
The orientation of the additional modification and in particular the orientation of the end relief is optionally freely specifiable within specific conditions. A triangular end relief is optionally specifiable. The orientation of the end relief is that direction in which the end relief drops the most. Alternatively, the orientation of the end relief can also be defined as that direction which stands perpendicular on lines of constant modifications of the end relief. It must, however, be taken into account that the modification resulting on the workpiece from this superposition no longer has any such lines of constant modification due to the superposition of the modification which can be represented in accordance with the present disclosure as a second degree polynomial.
The crowning can optionally be specified in a direction which stand perpendicular on the orientation of the additional modification and in particular perpendicular on the orientation of the end relief.
The diagonal ratio in the diagonal generating machining of the workpiece is optionally determined in dependence on a desired orientation of the additional modification and in particular of the end relief.
In a fourth aspect, which is optionally combined with at least one of the preceding aspects, the present disclosure comprises a method for producing a toothed workpiece having a modified surface geometry by a diagonal generating method by means of a modified tool and by means of a modification of the machine kinematics during the machining process of the workpiece. In accordance with the present disclosure, on the basis of a desired modification of the surface geometry of the workpiece, a modification of the surface geometry of the tool suitable for the production of said desired modification as well as a suitable modification of the machine kinematics during the machining process are determined. In accordance with a fourth variant, the modification of the surface geometry of the tool can be produced in that the position of the dresser with respect to the tool is varied during dressing in line contact in dependence on the angle of rotation of the tool and/or on the tool width position. In a second variant, the surface geometry of the tool can comprise a modification which can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a constant, linear and/or quadratic function, with the coefficients of this constant, linear and/or quadratic function being formed in a first direction of the tool which extends perpendicular to the first direction by coefficient function FFtC,1, FFtL,1 and/or FFtQ,1. The first and second variants can optionally be combined. Provision is made in accordance with the present disclosure that the desired modification of the workpiece is specifiable as a superposition of at least one crowning with an end relief of the workpiece. A new class of modifications made possible by the diagonal generating method is also specifiable here in accordance with the present disclosure. The modification of the surface geometry of the tool by the diagonal generating method is mapped onto the surface of the workpiece and thus produces a corresponding modification of the surface geometry of the workpiece which is superposed by a modification produced by the modification of the machine kinematics during the machining process of the tool and thus produces the desired modification.
The orientation of the crowning and/or the orientation of the end relief is/are optionally freely specifiable within specific conditions. A triangular end relief is in particular specifiable in accordance with the present disclosure. The orientation of the end relief is that direction in which the end relief drops the most. Alternatively, the orientation of the end relief can also be defined as that direction which stands perpendicular on lines of constant modifications of the end relief.
The shape of the end relief in a first direction of the end relief which optionally extends perpendicular to its orientation can optionally be described at least approximately by a quadratic function. Alternatively or additionally, the crowning of the end relief can be specifiable in a first direction of the end relief which optionally extends perpendicular to its orientation.
The orientation of the end relief, e.g. the direction in which the end relief drops the most, optionally has an angle >30° with respect to the line of action of the gear. This angle is further optionally >60° or >80°. The orientation of the end relief is optionally perpendicular on the line of action of the gearing. This provides an ideal rolling off on the end relief.
This is equivalent to a first direction of the end relief in which it can be described at least approximately by a quadratic function having an angle <60°, <30°, or <10° with respect to the line of action of the gearing. The line of action optionally extends in parallel with this first direction so that a crowning of the end relief results along the line of action.
Different end reliefs can furthermore be provided at the upper edge and the lower edge in accordance with the present disclosure. End reliefs having different orientations can in particular be provided in accordance with the present disclosure. Work is optionally carried out with different diagonal ratios for machining the two end reliefs.
The present disclosure in accordance with the fourth aspect is optionally combined with the first, second and/or third aspects. Alternatively or additionally, the specification of the crowning and/or of the end relief can take place as was already shown in more detail above with respect to the first, second and/or third aspects. The production of the modification can furthermore also take place such as was already shown above with respect to the first, second and/or third aspects.
In accordance with a fifth aspect, the present disclosure comprises a method of producing a toothed workpiece having a modified surface geometry by a diagonal generating method by means of a modified tool. In accordance with a first variant, a specific modification of the surface geometry of the tool is produced in that the position of the dresser with respect to the tool during dressing in line contact is varied in dependence on the angle of rotation of the tool and/or on the tool width position. In a second variant, a tool is used whose surface geometry comprises a modification which can be described at least approximately in the generating pattern at least locally in a first direction of the tool by a linear and/or quadratic function, with the coefficients of this constant, linear and/or quadratic function being formed by coefficient functions FFtC,1, FFtL, and/or FFtQ, 1 in a second direction of the tool which extends perpendicular to the first direction. The first direction of the tool optionally has an angle ρFS≠0 with respect to the tool width direction. In accordance with a third variant, a tool is used whose surface geometry comprises a modification whose pitch and/or crowning varies in dependence on the angle of rotation of the tool and/or on the tool width position. The second or third variant is optionally produced in accordance with the first variant and/or the third variant is combined with the second variant. The corresponding modification of the surface geometry of the tool is transferred to the workpiece by the diagonal generating method and produces a corresponding modification of the surface geometry of the workpiece there. Provision is made in accordance with the present disclosure that the desired modification of the workpiece is specifiable as a waviness having an amplitude which has a non-constant value transversely to the direction of propagation of the waviness. A new class of modifications can also hereby be produced in the diagonal generating method in accordance with the present disclosure.
An amplitude function is optionally specifiable which has at least one linear and/or quadratic shape transversely to the direction of propagation of the waviness and in particular along the wave peaks. One or more of the coefficients of a linear and/or quadratic amplitude function can in particular be freely selectable at least within specific conditions in accordance with the present disclosure. Alternatively or additionally, the amplitude can be specifiable such that it varies in every direction of the flank. Further alternatively or additionally, the amplitude can be specifiable in the generating pattern as a second degree polynomial in the rolling angle wF and in the workpiece width position zF.
Unlike in accordance with the modification in accordance with the fourth aspect, it is, however, in the present case not simply a superposition of a further function on a crowning. The modification which can be specified and produced in accordance with the fifth aspect is rather specified in accordance with the present disclosure by the product of the amplitude function specified in accordance with the present disclosure and of a wave-shaped function. This makes it possible to vary the size of the waves over the flank both in the direction of propagation and perpendicular to direction of propagation.
The orientation of the waviness is optionally freely selectable within specific conditions.
The modification in accordance with the fifth aspect is optionally produced in that the surface geometry of the tool used is approximately given in a first direction of the tool by a quadratic function or in that the crowning varies in dependence on the angle of rotation of the tool and/or on the tool width position. Such a modification optionally has a modification superposed on it which can be produced by a modification of the machine kinematics during the machining process and/or a modification is superposed which can be produced by the use of a modified dresser. FFtQ,1, i.e. the coefficient function for the quadratic portion of the quadratic function, can in particular be non-constant and can optionally depend linearly or non-linearly on the position in the second direction. The coefficient functions FFtC,1 for the constant portion and FFtL,1 for the linear portion of the quadratic function can be equal to zero, can be constant or can be non-constant. The coefficient function FFtC,1 for the constant portion is optionally a wave function.
The present disclosure comprises in accordance with a sixth aspect a method of producing a toothed workpiece having a modified surface geometry by a diagonal generating method by means of a modified tool. A specific modification of the surface geometry of the tool is produced in that the position of the dresser with respect to the tool is varied during dressing with line contact in dependence on the angle of rotation of the tool and/or the tool width position; wherein the modification of the tool by the diagonal generating method produces a corresponding modification on the surface of the workpiece. The modification on the workpiece produced by the modified tool can be described at least approximately in accordance with a first variant in the generating pattern at least locally in a first direction of the workpiece by a linear and/or quadratic function, with the coefficients of this linear and/or quadratic function being formed in a second direction which extends perpendicular to the first direction by coefficient functions FFtC,2, FFtL,2 and/or FFtQ,2. In accordance with a second variant, the modification on the workpiece produced by the modified tool can have a pitch and/or crowning in a first direction which varies in dependence on the angle of rotation of the workpiece and/or on the workpiece width position. Provision is optionally made that the first direction extends on the workpiece at an angle <60° to the line of action of the gearing. The first direction further optionally extends at an angle <30° or <10°, to the line of action of the gearing. The first direction optionally extends in parallel with the line of action of the gearing. This has the advantage in accordance with the present disclosure that the second direction of the workpiece in which the shape of the modification is substantially freely selectable has a correspondingly large angle to the line of action of the gearing and is optionally perpendicular thereon. A variety of modifications are thus possible perpendicular to the line of action. In addition, however, in accordance with the present disclosure, a modification can also be specified at a small angle and optionally in parallel with the line of action, said modification extending linearly and/or quadratically in accordance with the present disclosure. A crowning can, for example, be specified along this direction.
The procedure in accordance with the sixth aspect can in particular be combined with at least one of the first five aspects or can be used for the modifications shown there.
The method in accordance with the present disclosure can in principle also be used with non-dressable tools, in which the corresponding modification of the surface geometry is produced during the production process and is specified during the machining procedure of the workpiece. If it is a non-dressable grinding tool, the modification in accordance with the present disclosure of the surface geometry can be produced during the manufacturing process in exactly the same way as described in the following for dressable tools, with the only change that instead of a dressing tool, a corresponding manufacturing tool is used, for example a rolling die.
For the case that the tool is a hobbing cutter, it has to be manufactured in such a way that the enveloping body of the hobbing cutter has the modification provided in accordance with the present disclosure. With respect to a hobbing cutter, the term “modification of the surface geometry of the tool” as used in the context of the present disclosure is to be understood as a modification of the surface geometry of the enveloping body of the hobbing cutter.
The present disclosure is, however, optionally used with dressable tools. In particular, the modification of the surface geometry of the tool is generated during the dressing process.
Provision is optionally made that the modification of the surface geometry of the tool is produced by the modification of a relative position between the tool and the dresser during dressing, with the dresser optionally being in line contact with the tool during dressing and/or the first direction of the modification of the surface geometry of the tool corresponding to the line of action of the tool and/or being specified by it.
The dressing takes place on two flanks in a first embodiment. This can in particular take place when the surface geometry of the tool is to be given a modification by the dressing which can be described at least approximately on both flanks in the respective generating pattern at least locally in a first direction of the tool by a constant or linear function, with the coefficients of this linear function being formed in a second direction of the tool which extends perpendicular to the first direction by coefficient functions FFtC,1 for the constant portion and FFtL,1 for the linear portion. This can alternatively or additionally take place when the surface geometry of the tool is to obtain a modification on both flanks in each case by the dressing whose tooth thickness and/or pitch varies in dependence on the angle of rotation of the tool and/or on the tool width position or whose crowning does not vary in dependence on the angle of rotation of the tool and/or on the tool width position.
The dressing takes place on one flank, in contrast, in a second embodiment. This can in particular take place when the surface geometry of the tool is to obtain a modification by the dressing which can be described at least approximately in the generating pattern at least on one flank locally in a first direction of the tool by a quadratic function, with the coefficients of this quadratic function being formed in a second direction of the tool which extends perpendicular to the first direction by coefficient functions FFtC,1 for the constant portion and FFtL,1 for the linear portion and/or FFtQ,1 for the quadratic portion and/or whose crowning varies on at least one flank in dependence on the angle of rotation of the tool and/or on the tool width position. The dressing on one flank can also be useful if the pitch on the right flank deviates too much from the negative value of the pitch on the left flank or if a two-flank dressing is not possible for other reasons, e.g. because no suitable dresser is available.
In accordance with the present disclosure, the relative position of the dresser to the tool during dressing with line contact can be specifically set such that the contact line between the dresser and the tool is displaced on the dresser in order hereby to influence the active profile transferred to the tool along the contact line. The desired modification on the tool is optionally hereby produced. The pitch and/or crowning along the contact line on the tool can in particular be set or varied. This contact line on the tool optionally defines the first direction of the modification on the tool.
In general, the pitch of the specific modification of the tool in the context of the present disclosure is understood as the pitch in a first direction of the tool which includes an angle ρF1 other than zero with respect to the tool width direction and which in particular has a portion in the profile direction, e.g. the pitch of the modification corresponds to the profile angle difference.
Furthermore, a crowning of the modification of the tool in the sense of the present disclosure is understood as a crowning in a first direction which includes an angle ρF1 other than zero with respect to the tool width direction and which in particular has a portion in the profile direction, e.g. the crowning of the modification corresponds to a profile crowning.
Since the direction of the line of action of the dresser on the tool during dressing and thus the first direction of the modification of the surface geometry of the tool can, however, not be changed to any desired extent, the first direction of the modification of the surface geometry of the tool is at least not freely variable over a larger region. In accordance with the present disclosure, this requires a corresponding matching of the diagonal ratio to be able to select the first direction of the modification of the surface geometry of the workpiece over a larger region.
The pitch in a first direction of the workpiece which includes an angle ρF2 to the workpiece width direction is furthermore understood as the pitch of the specific modification of the workpiece in the context of the present disclosure, with the angle ρF2, however, also being able to be zero, but optionally not being equal to zero. A crowning in a first direction is furthermore understood as a crowning of the modification of the workpiece in the context of the present disclosure, with the angle ρF2, however, also being able to be zero, but optionally not being equal to zero.
The tool is optionally dressed in a modified manner by means of a profile roller dresser or a form roller. The profile roller dresser or the form roller in accordance with the present disclosure can in particular be rotatable about an axis of rotation and can have a rotationally symmetrical profile.
In accordance with a first variant, the profile roller dresser or form roller dresser can be in contact with the tooth of the tool during the dressing from the root region to the tip region so that the modification takes place over the total tooth depth in one stroke. A particularly fast dressing method hereby results.
In a second variant, the profile roller dresser or the form roller can only be in contact with the tooth of the tool in part regions between the root and the tip during dressing so that the specific modification takes place over the total tooth depth in a plurality of strokes and with a respectively different relative positioning of the dresser and/or with different dressers and/or using different regions of a dresser. The dressing method is admittedly hereby prolonged. However, more variations in the selection of the surface geometry of the tool are possible since the modifications of the surface geometry in accordance with the present disclosure can be selected separately for each stroke. The dressing optionally still takes place in line contact, however, so that a relatively efficient dressing method still results.
Independently of the selected variant, the modification of the surface geometry of the tool is optionally produced in that the position of the dresser with respect to the tool during dressing varies in dependence on the angle of rotation of the tool and/or on the tool width position, with the production of the specific modification on the tool taking place in that at least three degrees of freedom are used in the relative positioning between the dresser and the tool for producing the desired modification. Four or optionally even five degrees of freedom may be used. The degrees of freedom are optionally settable independently of one another for producing the desired modification.
Provision can in particular be made that at least three, four or all of the following five degrees of freedom are used for producing the specific modification on the tool: Angle of rotation of the tool; axial position of the tool; y position of the dresser; center distance; and/or axial cross angle.
The axial position of the tool, i.e. the tool width position, is optionally used to displace the contact line of the dresser on the tool. Two, three of four degrees of freedom of the remaining four degrees of freedom are optionally set independently of one another to produce the specific modification along the contact line.
Provision can be made in accordance with the present disclosure that a desired modification of the surface geometry of the workpiece is specified, wherein suitable coefficient functions FFtC,1, FFtL,1 and/or FFtQ,1 of the surface geometry of tool and a suitable diagonal ratio are determined in dependence on the desired modification of the surface geometry of the workpiece.
In this respect, in dependence on the desired modification of the surface geometry of the workpiece, a suitable variation of the position of the dresser with respect to the tool during dressing in dependence on the angle of rotation of the tool and/or on the tool width position and a suitable diagonal ratio are optionally determined. The suitable variation of the position of the dresser with respect to the tool during dressing is in particular determined such that the desired geometry respectively results along the first direction of the tool which is determined by the contact line of the dresser. The diagonal ratio is then selected such that the first direction of the tool is mapped onto the first direction of the workpiece.
A desired orientation of the modification of the surface geometry of the tool can furthermore be specified in accordance with the present disclosure and the diagonal ratio can be set such that the desired orientation of the modification results during diagonal generating machining.
In accordance with the present disclosure, the diagonal ratio is optionally kept constant at least over every stroke.
In addition to the method in accordance with the present disclosure, the present disclosure furthermore comprises a gear manufacturing machine for machining a workpiece using a tool in the diagonal generating method and/or for dressing a tool using a dresser in line contact for carrying out a method such as was described in more detail above.
The gear manufacturing machine can comprise a manufacturing machine with which a workpiece received in a workpiece holder can be machined by a tool received in a tool holder. The tool holder is optionally arranged at a machining head which has corresponding axes of movement for producing a relative movement between the tool and the workpiece for machining the workpiece. The workpiece holder and the tool holder each have axes of rotation whose movements can be coupled with one another to carry out the generating machining.
The gear manufacturing machine can comprise a dressing machine. It optionally has a dresser holder via which the dresser can be rotated about an axis of rotation. The dressing machine further optionally has a tool holder into which the tool is clamped and via which the tool can be rotated about its axis of rotation. Axes of movement are furthermore provided via which the relative movements required for the dressing in accordance with the present disclosure can be produced between the dresser and the tool.
The gear manufacturing machine in accordance with the present disclosure is optionally a combination of a manufacturing machine and a dressing machine. The dressing machine and the manufacturing machine optionally shape the tool holder. In this case, a tool clamped in the tool holder can be used, on the one hand, to machine a workpiece. It is furthermore possible to dress the tool clamped in this tool holder without the tool having to be unclamped and clamped in another tool holder again.
The axes of movement of the gear manufacturing machine are optionally NC axes. The gear manufacturing machine optionally has a control for controlling the NC axes of the gear manufacturing machine. The control is optionally programmed (e.g., instructions for the control are stored in non-transitory memory of a control system of the machine and executable by a processor of the control system), such that a method in accordance with the present disclosure can be carried out on the gear manufacturing machine. The control in particular has functions for carrying out a method in accordance with the present disclosure.
The gear manufacturing machine in accordance with the present disclosure is optionally configured such that at least one of the methods in accordance with the present disclosure described in more detail above can be carried out and optionally a plurality of the methods shown above. The gear manufacturing machine in particular has an input function via which the desired modification is specifiable. The input function in particular has input fields via which data on the specifiable modifications defined within the framework of the methods in accordance with the present disclosure can be input or via which the modifications specifiable in accordance with the present disclosure can be input into the machine control. The input function, and the other functions described herein, may be performed by a processor of the control system via execution, by the processor, of instructions stored in non-transitory memory of the control system.
The gear manufacturing machine optionally furthermore has a control function which produces the desired modification by a corresponding control of the machine kinematics within the framework of the dressing and/or machining of a workpiece. A calculation function is optionally provided for this purpose which determines a modification of the tool suitable for producing the desired modification of the workpiece and/or the changes of the machine kinematics suitable for producing the desired modification during the machining process and optionally during the dressing process. The gear manufacturing machine optionally works such as was described in more detail above with respect to the methods in accordance with the present disclosure.
The gear manufacturing machine can optionally have a selection function via which one of the modifications of the workpiece specified in more detail above can be selected from a list, with a plurality of the modifications shown in more detail above optionally being selectable. The parameters defining the modification can then optionally be able to be input into the input function according to this selection.
The present disclosure furthermore comprises a control system (e.g., a computer system) and/or a software program (e.g., which may be installed on/stored in non-transitory memory of the control system and executable by the control system) for determining the machining parameters suitable for producing a work piece having a desired modification for carrying out one of the methods such as were described above. The computer system optionally comprises a function for inputting a desired modification and a calculation function which determines the parameters of the machining process of the workpiece required for the production of the desired modifications from the desired modification of the workpiece and/or the required modification of the tool and/or the modification of the dressing process and/or of the dresser required for the provision of the modification of the tool.
The computer system and/or the software program optionally has the input functions which were already shown in more detail above with respect to the gear manufacturing machine in accordance with the present disclosure Alternatively or additionally, the input function can make possible the specification of the geometries in accordance with at least one, and optionally in accordance with a plurality of, the methods described in more detail above.
The computer program can optionally be installed on a gear manufacturing machine to be able to carry out a method in accordance with the present disclosure using the gear manufacturing machine. Alternatively, the computer program or the computer system can have an output function for data for use on a gear manufacturing machine. The changes of the machine kinematics during the dressing process and/or the parameters of the machining procedure on the gear manufacturing machine can optionally be specifiable and/or determinable by the computer system and/or by the software program.
Some features will be described again in the following which relate to all aspects of the present disclosure:
The generating machining method in accordance with the present disclosure is optionally a generating grinding method. The tool which is dressed or used in accordance with the present disclosure is optionally a grinding worm.
The method in accordance with the present disclosure and the apparatus or tools in accordance with the present disclosure are optionally configured such that an involute gearing is produced in accordance with the present disclosure on the workpiece. The modifications of the surface geometry of the tool and/or of the workpiece which are used or which can be produced in accordance with the present disclosure are therefore optionally modifications of an involute surface geometry.
With respect to the function defined in accordance with the present disclosure which at least approximately describes the modification of the tool or of the workpiece and which can be descried at least approximately in the generating pattern in a first direction by a constant, linear and/or quadratic function, with the coefficients of this constant, linear and/or quadratic function being formed in a second direction which extends perpendicular to the first direction by coefficient functions FFtC,1/2, FFtL,1/2 and/or FFtQ,1/2, FFtC,1/2 can be the coefficient function for the constant portion, FFtL,1/2 can be the coefficient function for the linear portion and FFtQ,1/2 can be the coefficient function for the quadratic portion of the modification of the tool or of the workpiece in the first direction.
FFtC,1/2 is optionally non-constant and further optionally depends non-linearly on the position in the second direction. FFtL,1/2 is furthermore optionally non-constant and further optionally depends linearly or non-linearly on the position in the second direction. FFtQ,1/2 can be equal to zero or can be constant in a first embodiment of the present disclosure. In a second embodiment, FFtQ,1/2 can be non-constant and can optionally linearly or non-linearly depend on the position in the second direction.
The modification of the workpiece or of the tool can optionally be described not only locally, but also at least in a part region of the gearing and optionally also globally over the total gearing at least approximately by the constant, linear and/or quadratic function which may have been specified in more detail above, with the coefficients of this constant, linear and/or quadratic function being formed in a second direction which extends perpendicular to the first direction by coefficient functions FFtC,1/2 for the constant function and FFtL,1/2 for the linear portion and/or FFtQ,1/2 for the quadratic portion.
If it is stated in the present application that a modification can be described at least approximately by a specific function, this optionally means that the specific function describes the modification within the framework of a specified permitted tolerance and/or that the difference between the specific function and the modification lies within a specified permitted tolerance range. The method in accordance with the present disclosure can include the step of specifying a permitted tolerance and/or a permitted tolerance range. The gear manufacturing machine in accordance with the present disclosure or the computer system or computer program can furthermore comprise a function for specifying a permitted tolerance and/or a permitted tolerance range.
The present disclosure will now be explained in more detail with reference to embodiments and to drawings.